Mains-powered electrical appliances are typically connected to a mains power supply through an electrical cable that connects to the mains power supply with a plug. In many countries, it is a regulatory requirement that the electrical cable is appropriately secured to the electrical appliance for safety reasons. For example, in case of the electrical cable being pulled, the electrical cable should remain secured to the electrical appliance such that the live terminals of the electrical cable cannot become exposed due to the electrical cable disconnecting from the electrical appliance, which would cause an immediate safety hazard. For example, in China, the China Compulsory Certification (CCC) regulation requires that an electrical wire connected to an electrical appliance such as a luminaire is secured to the appliance for this reason.
Several solutions exist for securing electrical cables. FIG. 1 schematically depicts a prior art clamp 10 having a pair of cable thread holes 11 through which an electrical cable 1 may be threaded to secure the cable to the clamp 10. FIG. 2 schematically depicts the electrical cable 1 threaded through the cable thread holes 11 of the clamp 10. The cable thread holes 11 are typically dimensioned such that the electrical cable 1 snugly fits into the cable thread holes 11, thereby retaining the electrical cable 1 through friction. Such a clamp 10 for example may be used to prevent coiling of the electrical cable 1, but is unsuitable for retaining the electrical cable 1 in an electrical appliance because the clamp 10 cannot be easily secured to or within the electrical appliance.
FIG. 3 schematically depicts a well-known assembly for securing an electrical cable to the body of an electrical appliance. The assembly comprises a bridge member 20 having opposing cylindrical body portions 22 including screw holes 21 for receiving screws 23. The opposing cylindrical body portions 22 are interconnected by a bridge portion 24 spanning over a gap 25 for receiving the electrical cable 1. The height of the gap 25 is typically less than the thickness of the electrical cable 1 such that when the bridge member 20 is screwed to an anchoring member 27 on the body 3 of the electrical appliance using the screws 23 as schematically depicted in FIG. 4, the resilient electrical cable 1 is squeezed (gripped) between the bridge member 20 and the anchoring member 27. Consequently, the release of the live terminals of the electrical from the electrical connectors 4 of the electrical appliance is prevented by this assembly if the electrical cable 1 is suddenly pulled.
Although this assembly ensures that the electrical cable 1 is safely secured to the electrical appliance, a drawback of this assembly is that it requires a hand tool, e.g. a screwdriver, to secure the electrical cable 1 onto the electrical appliance. This can be cumbersome in particular in situations where the electrical appliance needs to be installed in a space that is difficult to access, for example the installation of a luminaire in a ceiling, where the electrical cable 1 is typically hidden in a dead space above the ceiling that can only be accessed through the holes in the ceiling in which the luminaire is to be fitted.
GB 2 300 219 A discloses an assembly for clamping a cable relative to a body. The assembly comprises a clamping element having clamping surfaces between which, in use, the cable is disposed; and a formation on said body adapted to engage with said clamping element to cause said clamping surfaces of said element tightly to grip a cable disposed therebetween. This assembly is relatively complex and therefore costly.